In recent years we have heard a lot about "colony collapse" in reference to honey bee colonies. As honey bees pollinate many of our crops, including all stone fruit, apples, pears, and many others, this has become a major worry in the agricultural community. The latest thinking seems to involve both parasites and pollution, including pesticides. Despite the impression of many the honey bee is not native to the New World. The genus Apis appears to have evolved in Southeast Asia, with one species spreading into Europe and Africa. The first honey bees were brought to the New World by the early colonists and were accidentally released into Massachusetts (and very likely in the Spanish colonies in the Southwest) in the early 1600s. When the honey bee was released into Australia, it caused a decline in native bees and this probably occurred also in North America, but no one was there to record it. One of my colleagues who worked at the Carl Hayden Bee Research Center called them "pollen pigs." Still they were vital for the pollination of our Eurasian fruit and vegetable crops and they produced honey and bee's wax. Thousands of hives are transported by flatbed truck from Florida to California and around the country in order to pollinate our almonds, apples, cherries, apricots, peaches, citrus, etc.
However, honey bees are not by any means the only bees in North America, nor are they the only ones in danger from human activities, especially pesticides and habitat degradation. Leaf-cutter bees (Megachile spp.) are very important in the pollination of alfalfa and the related blue mason bees (Osmia lignaria) is very important in the pollination of tree crops. Both are members of the Megachilidae and both are native to the U.S. (although one of the blue bees has been imported) and have become more involved in crop production. Nesting boards drilled with bee-sized holes are commonly used to maintain "colonies" (leaf-cutter bees and mason bees are actually solitary, but will nest together.) Beside these the North American fauna of bees is huge and includes bumble bees (excellent pollinators of clover), digger bees, white-faced bees, "sweat bees", etc.
Bees are, of course, not the only pollinators. These include bees, wasps, beetles, butterflies, some moths, many flies, as well as some birds, bats, and even a few small non-flying mammals. Many agaves (source of tequila) are, in fact, pollinated by bats, as are some night-blooming cacti. Adult long-horned beetles and others are often covered with pollen when they feed on composite (Asteraceae) flowers and metallic wood-boring beetles similarly pollinate mesquite and composites and may be coated with pollen. Pollination is complex and some plants depend on wind, rather than pollinators (most grasses) or do not reproduce sexually, but by rhizomes, bulbs or runners. Still there are a huge number of vascular plants that depend on animals, often bees. Bees are certainly very important for the seed production of many of our crop species and their destruction would cause havoc to agriculture.
What can be done? Anything that increases habitat, increases alternate pollen and nectar sources, and reduces stress by pesticides, pollution and parasites, would certainly be useful. I plant bee-friendly annuals, such as sunflowers, basil, umbelliferous plants, clovers, etc. Little by little I have been drawing large, medium sized and even tiny Perdita bees only 2-3 mm long. Bumble bees, which have been rare in the garden of late, are starting to return, visiting the cherry sage. Long-horned and digger bees, as well as carpenter and leaf-cutting bees and of course honey bees, are showing up in fair numbers, as are hummingbirds, butterflies and occasional wasps and flies. They still are not at levels as high as they were years ago, but the numbers are better than earlier recent summers.
This year I am setting up an insect observation garden, with paths and irregular beds to be planted with bee, butterfly and hummingbird mixes, sunflowers, poppies, salvia, basil and other favorites. Perhaps I'll set up some bundles of hollow reeds and/or drilled "bee boards" to see if I can lure leaf-cutting and mason bees to nest. I do not use pesticides (unfortunately I can't speak for my neighbors) and I occasionally pay for this by loosing some plants, but usually everything works out reasonably well.
A Honey Bee (Apis mellifera) takes off from the blooms of a Seep Willow at the Mesilla Valley Bosque State Park, New Mexico. A Western Pigmy Blue to lower right. Note pollen basket (Corbicula) on hind legs of Honey Bee.
Carpenter Bee (Xylocopa sp.) on Bird of Paradise, Broad Canyon, New Mexico.
Leaf-cutting Bee (Megachilidae) on Sunflower, Mesilla Park, New Mexico. Note pollen being carried on special hairs on underside of abdomen.
Buchmann, Stephen, and Gary Paul Nabhan. 1996. The Forgotten Pollinators. Island Press, Washington, DC.
Grissell, Eric. 2010. Bees, Wasps, and Ants: The Indispensable Role of Hymenoptera in Gardens. Timber Press, Portland, Oregon.
The Xerces Society. 2011. Attracting Native Pollinators. Storey Publishing, North Adams, Massachusetts.
Attracting Pollinators to Your Garden Using Native Plants. https://docs.google.com/...
Ahn,Kiheung, Xianbing Xie, Joseph Riddle, Jeff Pettis, and Zachary Y. Huang. 2012. Effects of Long Distance Transportation on Honey Bee Physiology. Psyche. http://www.hindawi.com/...
Pollinator Partnership. http://www.pollinator.org/
Note: All photos are by me.